Shown are fast-spiking auditory neurons in the mouse brainstem, filled with hydrazide (green) from patch-clamp recordings. These neurons receive input from calyx of Held nerve terminals that are morphologically and functionally diverse, labelled with dextran (magenta). A Hoescht stain (blue) marks all cell nuclei. The intrinsic excitability of these fast-spiking neurons are aligned to the strength of presynaptic calyx inputs, diversifying spiking patterns. See the article by Raphael J. Chan and Lu-Yang Wang for more information on this organization of synaptic inputs that expands information coding capacity. Cover image: Raphael Chan.